1. Field of the Invention
An apparatus consistent with the present invention relates to a multi-stage operation type air conditioner and, more particularly, to a multi-stage operation type air conditioner, which is able to operate with a variety of cooling or heating capacities.
2. Description of the Related Art
Generally, a conventional air conditioner consists of one indoor unit and one outdoor unit. The indoor unit is equipped with an indoor heat exchanger for exchanging the heat of air in a room, and with a discharge port for discharging chilled air in the indoor unit to the outside of the indoor unit. The outdoor unit is equipped with a compressor for compressing a refrigerant, an outdoor heat exchanger for exchanging the heat of outside air, and an electronic expansion valve for expanding the refrigerant.
In such a conventional air conditioner, when a user inputs an operating command, a microcomputer in the air conditioner controls the number of rotations of the compressor (in the case of a rotary compressor), or controls an opening of a motor operating valve and the number of rotations of a blowing fan, based on data input through various sensors, thereby allowing a temperature in the room to reach a desired temperature. That is, when the user sets a high stage operation accompanied with a large quantity of air discharge, the microcomputer increases the number of rotations of the compressor, and the number of rotations of the blowing fan, thereby increasing a cooling or heating capacity, or when the user sets a low stage operation, the microcomputer lowers the number of rotations of the compressor, and the number of rotations of the blowing fan, thereby decreasing the cooling or heating capacity.
However, such a conventional air conditioner has a problem in that, since a degree of variation in cooling or heating capacity by changing the number of rotations of the compressor and the number of rotations of the blowing fan is small, an appropriate cooling or heating according to a variation of cooling or heating load cannot be performed. For instance, in a case where an air conditioner having a rated load for cooling or heating only a living room is equipped in a living room of an interior space consisting of three rooms and one living room, and is then used with the two rooms opened, even if the air conditioner is operated with the maximum cooling or heating capacity, a pleasant conditioned state cannot be achieved since the degree of variation in a temperature of the interior space is small.
On the contrary, in a case where the air conditioner is equipped for cooling or heating only one room, and the room is partitioned into two small rooms, the air conditioner performs a cooling or heating operation for one small room with a compressor having a compressing capacity larger than the compressing capacity needed for the small room, and with a heat exchanger having a heat exchanging capacity larger than the heat exchanging capacity needed for the small room, thereby consuming an unnecessary amount of energy.